/*-
* SPDX-License-Identifier: MIT
*
* Copyright (c) 2005-2014 Rich Felker, et al.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <limits.h>
#include <stdint.h>
#include <string.h>
#define SS (sizeof(size_t))
#define ALIGN (sizeof(size_t) - 1)
#define ONES ((size_t)-1 / UCHAR_MAX)
#define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
#define HASZERO(x) (((x)-ONES) & ~(x)&HIGHS)
void *
memchr(const void *src, int c, size_t n)
{
const unsigned char *s = src;
c = (unsigned char)c;
#ifdef __GNUC__
for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--)
;
if (n && *s != c) {
typedef size_t __attribute__((__may_alias__)) word;
const word *w;
size_t k = ONES * c;
for (w = (const void *)s; n >= SS && !HASZERO(*w ^ k);
w++, n -= SS)
;
s = (const void *)w;
}
#endif
for (; n && *s != c; s++, n--)
;
return n ? (void *)s : 0;
}
